Chapter 8 Flashcards
Factors to consider when choosing an extinguishing agent are:
Expense
Availability
How well it works (efficiency)
___ and the ___ of the extinguishing agent are two closely related topics.
Fire behavior
Properties
At ___ and up water becomes a gas (steam).
212°f
At 212°f water expands ___ times it original volume and the hotter the temp the greater the expansion.
1,700 times
Water extinguishes fire in 3 ways:
Cools the burning material
Smothers the fire
Separates the fuel form the heat
When converted to steam, water can smother the fire by displacing the oxygen in the room but ___ the fire remains the main reason water extinguishes fire.
Cooling
The amount of water needed is known as the ___.
Flow requirement
NFA formula:
NFF = ((Length x width) / 3) x percentage of building involved
Iowa formula:
NFF = V(volume)/100
___: Most widely used, many variations; adjustable gallonage, automatic gallonage, fixed gallonage, and low pressure and high pressure.
Fog nozzles
___ have better cooling capabilities than any other nozzle, because of the thousands of tiny droplets of water increasing surface area, but they can disturb the natural thermal layers of afire if applied incorrectly.
Fogs
Proper ___ is critical to the proper use of fog nozzles.
Ventilation
Problem with fog nozzles, require ___ psi at the nozzle to create an effective stream.
100 psi
New fog nozzles are capable of operating effectively at pressures less than 100 psi, typically ___ psi.
75 psi
One of the benefits of a ___ is it creates a stream that does not generally disturb the thermal layers of the fire or push the heat and gasses into other areas, which can increase the survivability for occupants and typically results in fewer steam burn injuries to firefighters.
Smooth bore
Most ___ have a special type of application; for example a ___ nozzle or a ___ nozzle. In both of these nozzles, the application of water is done blindly.
Broken stream nozzles
Piercing nozzles or a cellar nozzle
All of the friction loss formulas figure friction loss in ___ feet of hose.
100 feet
A simple friction loss formula is:
FL = Q(Q+Q+1)
The formula for determining GPM is:
GPM = 29.7(D)² x √NP
___ generally, has been created for HAZMAT and Class A fires.
Foam
Foams are commonly used for 2 basic types of haz-mats: ___(petroleum based) and ___(alcohol based).
Hydrocarbons (petroleum based)
Polar Solvents (alcohol based)
Foam has 4 components:
air, water, foam solution, and agitation
___% or more of foam is water.
90%
Most manufacturers of foam require that they be proportioned at ___% for polar solvents and ___% for hydrocarbons.
6%
3%
Application of foam depends on the ___, the ___, the ___, and the ___.
Type of foam used
Type of incident
Topography
Equipment used
Aqueous film forming foam, AFFF, and film forming floor protein foams are generally ___ for hydrocarbons and ___ for polar solvents.
.10
.24
AFFF alcohol type concentrate is applicable to both classes; 3% for hydrocarbons and 6% for polar solvents. It an be used on ___ if proportioned very low (___%).
Class A
1%
Use of class A foams has grown in recent years due to woodland application and it has very low proportion rates, usually less than ___%.
1%
___ foam acts as an AFFF ATC-type foam but can be used on both polar solvent and hydrocarbons at 3%.
Gold foam
Bubbles from CAFS stay together longer and provide a ___% better drain time for the foam.
25%
Dry chemical extinguishers can be used as A-B-C (___) or B-C (___) extinguishers.
Multi-purpose
Ordinary-purpose
Common dry chem extinguishers in B-C:
Sodium bicarbonate
Potassium bicarbonate
Potassium chloride
Common dry chem extinguishers in A-B-C:
Mono-ammonium phosphate
Barium sulfate
Ammonium phosphate
___ are special purpose agents used for specific applications such as combustible metals (___).
Dry powders
Class D
Wet chemical extinguishers = ___.
Class K
___ is used primarily on class B and C fires and come in portable or wheeled extinguishers, and work by smothering.
Carbon Dioxide (CO²)
___: An extinguishing agent available in the 1980’s and early 1990’s.
Halon
Halon… Banned from production under the ___ because it depletes ozone.
Clean Air Act of 1994
Once discharged, Halon systems can only be refilled with ___ or ___.
Recycled Halon or a different agent
Two types of Halon; ___ (liquid) and ___ (gas).
Halon 1211 (liquid)
Halon 1301 (gas)
Halon… ___ was primarily used for protecting sensitive electronic equipment because it did not leave a residue; also used on high end boats and yachts.
Halon 1301
___: The pressure on a water distribution system during normal demand.
Normal Operating pressure
___: The tactic of introducing foam at he bottom of a bulk storage tank, allowing the foam to float to the top and blanket the product.
Subsurface Injection
___: Water soluble compounds such as alcohol; require foams that are alcohol-type concentrates (ATC).
Polar Solvents
